In recent years, a number of systems and methods have been used for occupancy counting within a particular area. Examples of such systems include video sensor monitoring systems, thermal sensor systems, infrared systems, global positioning systems (GPS), and wireless communication systems. However, many of these systems have disadvantages. For example, the video sensor monitoring system requires a considerable amount of dedicated sensors that are expensive or cameras that need consistent lighting to record, and that require a large amount of memory for storing data. Often, infrared systems mounted on doors/frames at entry points and are less accurate, especially when more than one person or an object crosses or breaks the light beam upon entry to or exit from the area. The GPS sensor system uses orbiting satellites to communicate with the terrestrial transceiver to determine a location of the occupant in the area, requires each person to have a device capable of receiving satellite signals, and communicates location results to a server or the like that does the counting. However, such GPS based systems are generally less effective indoors or in an environment in which satellite signals can be blocked, thereby, reducing accuracy of counting an occupant in the area.
Electrically powered artificial lighting has become ubiquitous in modern society. Since the advent of light emitters, such as lighting emitting diodes (LEDs), for general lighting type illumination application, lighting equipment has become increasingly intelligent with incorporation of sensors, programmed controller and network communication capabilities. Automated control may respond to a variety of sensed conditions, such as a daylight or ambient light level and occupancy. Commercial grade lighting systems today utilize special purpose sensors and related communications to aide in occupancy detection, for example, to turn on light when a room is occupied and to turn the light off when the room is no longer occupied for some period or to adjust a HVAC system.
A need exists for providing an improved system and method of counting or more accurately estimating the number of occupants in an area.